A machine tool of this type is disclosed in patent documents 1 and 2, for example. In each of these conventional structures, a driving unit exchanges a tool by using the tool exchanger arm, and opens and closes a shutter attached to an opening of a device. To achieve this structure, the device disclosed in patent document 1 includes a cam mechanism and a link mechanism to form a power transmission mechanism between the shutter and the driving unit. Further, the device disclosed in patent document 2 includes multiple cams, gears, etc. to form a power transmission mechanism between a driving shaft used for operating the tool exchanger arm and a door.
Each of the devices disclosed in the patent documents includes the power transmission mechanism provided between the driving unit and the door in addition to another power transmission mechanism provided between the driving unit and the tool exchanger arm. Specifically, each of these devices includes power transmission mechanisms of two systems, complicating the structure of the device.